li {
    list-style:none; width:300px;
    float:left;
    margin:10px
}
li dt {
    overflow: hidden;
    text-align: center;
    padding-bottom: 100%!important;
    position: relative;
}
li dt img {
    width: 100%;
    max-height: 200px;
    transition: all 1.2s;
    -moz-transition: all 1.2s;
    -webkit-transition: all 1.2s;
    -o-transition: all 1.2s;
    object-fit: cover;
    position: absolute;
    top: 0;
    left: 0;
    display: block;
    height: 100%;
    width: auto;
    min-height: 100%;
    min-width: 100%;
    max-width: 300%;
}